Chronic Ongoing Stressors and C-Reactive Protein: A Within-Person Study

Prospective network analysis of proinflammatory proteins, lipid markers, and depression components in midlife community women

BACKGROUND

Vulnerability theories propose that suboptimal levels of lipid markers and proinflammatory proteins predict future heightened depression. Scar models posit the reverse association. However, most studies that tested relationships between non-specific immune/endocrine markers and depression did not separate temporal inferences between people and within-person and how different immunometabolism markers related to unique depression symptoms. We thus used cross-lagged prospective network analyses (CLPN) to investigate this topic.

METHODS

Community midlife women (n = 2224) completed the Center for Epidemiologic Studies-Depression scale and provided biomarker samples across five time-points spanning 9 years. CLPN identified significant relations (edges) among components (nodes) of depression (depressed mood, somatic symptoms, interpersonal issues), lipid markers [insulin, fasting glucose, triglycerides, low-density lipoprotein-cholesterol (LDL), high-density lipoprotein-cholesterol (HDL)], and proinflammatory proteins [C-reactive protein (CRP), fibrinogen], within and across time-points. All models adjusted for age, estradiol, follicle-stimulating hormone, and menopausal status.

RESULTS

In within-person temporal networks, higher CRP and HDL predicted all three depression components (d = 0.131-2.112). Increased LDL preceded higher depressed mood and interpersonal issues (v. somatic symptoms) (d = 0.251-0.327). Elevated triglycerides predicted more somatic symptoms (v. depressed mood and interpersonal problems) (d = 0.131). More interpersonal problems forecasted elevated fibrinogen and LDL levels (d = 0.129-0.331), and stronger somatic symptoms preceded higher fibrinogen levels (d = 0.188).

CONCLUSIONS

Results supported both vulnerability and scar models. Long-term dysregulated immunometabolism systems, social disengagement, and related patterns are possible mechanistic accounts. Cognitive-behavioral therapies that optimize nutrition and physical activity may effectively target depression.

How Midlife Chronic Stress Combines with Stressful Life Events to Influence Later Life Mental and Physical Health for Husbands and Wives in Enduring Marriages

Objectives: To investigate how midlife chronic stress (40-50 years) and subsequent acute stressful events (50-65 years) influence husbands' and wives' later life mental and physical health (65+ years). Methods: Dyadic structural equation modeling was used with prospective data over 25 years from 256 husbands and wives in enduring marriages. Results: For both spouses, midlife chronic stress influenced the occurrence of subsequent acute stressful life events, which in turn influenced both depressive symptoms and poor physical health in later years. For both spouses, midlife chronic stress also directly influenced depressive symptoms. Wives' midlife chronic stress also directly influenced their own poor physical health and husbands' depressive symptoms in later years. Discussion: These findings enhance our knowledge about the long-term joint influence of midlife chronic stress and acute stressful life events on health outcomes of husbands and wives in later years and identify dependencies between spouses, which can inform health preventive intervention programs.